Gary Barlow has revealed that Take That have been recording more new songs as a five-piece.
The singer - who celebrated his 40th birthday this week - told BBC Radio 2 Robbie Williams was continuing to work with them in the studio, although he was unsure whether the tracks would form a new album.
It comes just days after Gary said during an interview that he thought of the group as "a four-piece", without Robbie, who rejoined the line-up after a 15-year absence for latest album Progress.
But interviewed during a special show to mark his milestone birthday, Gary said Robbie was always welcome in the group. "I want it to be that [Robbie] can be here whenever he wants and when he doesn't want to we'll be back as a four-piece, and if Rob wants to go and be solo then great, but please come back one day. I want to make it that fluid," he said.
The Rule the World singer insisted that when Robbie returned to the group, no dates had been set in stone for how long he would stay.
"We can exist and be successful as a four-piece band. Right now we are a five-piece band and we don't really know where that's going to at this point," he added.
"We're actually back recording right now, new songs. I don't think it's going to be a new record, I think its going to be an addition.
"I don't think we feel like we'd said it all when we got to the end of this record and we want to add to it, so we're already back writing and recording as a five-piece again."